A vehicle navigation apparatus detects a current car position by Global Positioning System (GPS), and displays a map around the current car position on the screen of a display unit. Further, the navigation apparatus indicates the current car position on the map, so that the car travels toward a desired place smoothly with the support of the navigation apparatus.
In addition, when a destination is set in the vehicle navigation apparatus, the navigation apparatus searches for guidance courses from a departure place (usually, from the current position) to the destination, and the guidance course is displayed with a color that is different from a normal road color on the map of the display unit, and the guidance course is guided for a travel guidance toward at the crossings or the like in terms of the progress direction by providing voice guidance or the like.
In the vehicle navigation apparatus that is capable of providing course guidance, there are various kinds of destination setting methods such as by an input of the phone number, by the address, by the name and the like. In the case of a destination search by the address, street name input are necessary because, in Europe and America in particular, street names are used to represent an address of a house (for example, referred to Japanese patent documents JP-A-H06-251295 and JP-A-H09-212086). In addition, a destination address search method by an input of a street name is designated by a name of “destination search” in the following description.
In Europe and America, the name of the street consists of plural parts (In this case a “part” indicates a portion of an entire name of a street or the like). The plural parts include a part called a body (Body, the subject or main part of the name) which is the proper noun of the street, a prefix and a suffix in front or behind the subject part (Prefix: a head and Suffix: a tailpiece) which indicates attributes such as a direction or the range of the street, and a street type (Avenue, Road or the like). In the following discussion, when the street name is represented by using all of the body, prefix/suffix and the street type, it is designated as a formal name (a full name of a street), and when the street name is represented by using only of the body, it is designated as a body name (a distinguishable name of a street among other streets).
Conventionally, vehicle navigation apparatus has two model types, that is, a model that demands the formal name of the street as the street name input (i.e., choosing a street from a street name list and specifying the street as, for example, the destination) and a model that demands the body name of the street as the street name input in an address search. However, when an address is represented in Europe and America, only the body name is used with other parts omitted in many occasions, (e.g., a signboard on a roadside which displays the name of a street, an invitation letter or the like). Thus, it is generally assumed that the body name is very likely recognized as the street name.
When the navigation apparatus is a model that demands the formal name input, a user cannot search for a street when only the body name of the street is known. For example, when the body name is input to the model that demands the formal name of the street, all of the streets with the body name are listed in the formal names. Therefore, the user must choose a desired street to from the listed streets. However, if the user does not know the formal name of the street, the street search stalls at that point. That is, the street can not be searched any further. Therefore, in Europe and America, people tend to prefer the navigation apparatus of a model that performs the street search by the body name.
On the other hand, if the navigation apparatus is the model that demands the body name input, the street search stalls when other parts are input besides the body part. That is, in this case, even the list of the street names cannot be displayed. For example, when the user inputs a street name by referring to a business card or the like, and the business card only lists the formal name of the street, the street name may be input in the formal name format as appeared on the card, thereby making it impossible to search an address based on the input street name.